1. Technical Field
This invention relates generally to shaft seals, and more particularly to those having features that enable the seal to be removed from a bore after installation.
2. Related Art
Automotive air conditioning compressor seals that require removal for service rely on three know methods for providing a surface that can be engaged by a tool so that the seal can be removed once it is installed in a bore. One approach is to provide a recessed step in the outer casing of the seal. Such a recessed step is difficult to manufacture consistently and the removal tool must be capable of exerting sufficient inward radial force in order to grip the recessed step with sufficient strength to enable the seal to be pulled from the bore. Another approach is to add a separate pull ring component to the seal assembly. An example of this type is shown in U.S. Pat. No. 4,623,153. This involves stamping the separate ring piece with slots and tabs and then clamping this piece between the inner and outer seal cases. This approach adds cost and complexity to the manufacture of seals. The third known approach utilizes the end flange of the outer case that is curled over the end of the inner case to secure the cases together and to clamp the seal element between the cases. The curled end flange is extended beyond the inner case to present a tool-engaging edge. However, the curl over is often thinner than the rest of the outer casing and is prone to tearing out under the extraction force of the tool or doesn't have sufficient length to allow easy removal.